(1) Field of the Invention
The present invention relates to a power steering system which obtains an assistance force of a steering operation according to an actuation of a pump.
(2) Description of Related Art
A Japanese Patent Application First Publication (tokkai) No. 2005-255001 published on Sep. 22, 2005 (which corresponds to a United Patent Application Publication No. 2005/0205338) exemplifies a previously proposed power steering system for an automotive vehicle in which a main pump which is driven by an engine and a sub pump is driven by an engine are installed and a steering assistance can be made even during an engine stop by a drive of the sub pump when the main pump is in an abnormal state.